AT RISK: The very lives of US soldiers, like these in Afghanistan yesterday, are imperiled by the McChrystal case. Photo: Reuters

Truth is no defense to in subordination. For the good of the troops, the mission and the entire military command structure, Gen. Stanley McChrystal must be sacked.

It matters not a whit whether McChrystal is factually correct in his caustic view of President Obama and members of the national security team. Nor does it matter whether his conduct and that of his aides rise to the legal level of insubordination.

Obama is the commander-in-chief and McChrystal is a cog in the chain of command. The general has exposed himself as the weak link with his foolish decision to go public with his complaints.

It’s probably true, as McChrystal told Rolling Stone magazine, that Obama was “disengaged” and not prepared for their first meeting on Afghanistan. More important is that McChrystal was so reckless as to say it to a magazine.

It may well be true that National Security Adviser Jim Jones is a “clown,” as the general charged. Jones, after all, opened an important meeting with an Israeli-friendly think tank with a joke about a heartless Jewish merchant.

Guilty as charged, but it’s not for McChrystal to make the charge. And Vice President Joseph Biden — who doesn’t make fun of him? But you can’t do it on the record when you have 100,000 American soldiers under your command, as well as forces from NATO allies.

And you certainly can’t charge our ambassador to Afghanistan with personal betrayal, as McChrystal did, and get away with it.

Any one of these comments would be cause for serious concern. So many broadsides against the civilian commanders of the United States in a time of war are simply beyond the pale.

The pattern shows such egregiously bad judgment that McChrystal’s credibility is wrecked. He can’t be trusted to lead or follow if he can’t be trusted.

The decorated general has apologized for the big-time screw-up, and no decent American can wish him any further humiliation when he meets the brass and a “furious” Obama after being summoned home. But neither his distinguished service nor the importance of the troubled war effort can be reason to spare him. There can be no such thing as “indispensable” or “too big to fail” in the military.

Gen. Douglas MacArthur, the supreme commander of allied forces fighting in Korea, was an even more important figure when he was sacked after a similar criticism of President Harry Truman in 1951. MacArthur thought Truman too hesitant in combating Chinese and North Korean forces, and expressed his barbs in a letter to a congressman — who promptly read its contents on the House floor. Abraham Lincoln bounced several top Union commanders in the Civil War.

The principle is the same now as always. Subjecting top commanders to strict standards of accountability ensures cohesion and trust up and down the chain.

To excuse McChrystal’s conduct on the basis of his rank would be to admit a double standard. That can damage the mission and cost the lives of ordinary soldiers.

The Afghan war effort needs victories, not another problem. Our casualties continue to rise, our allies are losing heart, and the government of Hamid Karzai barely functions outside the capital. New reports of vast bribes paid to warlords to protect our supply convoys will only add to the pressure on Obama to head for the exit. And growing complaints from our soldiers, including those in Rolling Stone, that rigid limits on the use of firepower are adding to the dangers can only reinforce public doubts.

It is a devilishly complex war, already the longest in American history. McChrystal, the author of the counterinsurgency plan and the surge Obama endorsed, appeared uniquely qualified to lead it. That appearance has been shattered and can’t be repaired.

Problem of ‘absent’ minds

Mayor Bloomberg is keeping an important promise he made on the campaign trail — to focus on city students who miss too many days of school.

You don’t need to be an educator to know you can’t teach a kid who isn’t in the classroom. Attendance in elementary grades turns out to be an extremely reliable predictor of success or failure in high school. As Bloomberg said in announcing a task force to come up with answers, “Three out of four students who are chronically absent in sixth grade never graduate from high school.”

Although average attendance among all students is 90 percent, an improvement over a decade ago, nearly one in five elementary students are absent 20 days or more — the definition of chronic absenteeism.

John Feinblatt, the mayor’s chief policy adviser and the man in charge of the task force, told me the city has good records on attendance, but wants to use the data “proactively.”

“When elementary kids miss a lot of school, it usually indicates a problem in the family that needs intervention,” he said. “It could be neglect, domestic abuse or parents who are disconnected from the school system.”

Courts, health and youth officials, homeless shelters and police all have pieces of the puzzle. The goal is to bring them together, along with national experts, to mine the data and energize the effort to get those kids back in the classroom.

This is a big deal. The futures of many kids hang on its success.

DAVE THE RIPPER

Gov. Paterson is up to his old tricks again. My colleague Fred Dicker’s exclusive report that someone on Paterson’s team called Lt. Gov. Richard Ravitch a “crybaby” echoes earlier smear campaigns by Paterson’s staff.

Not long after he took office, Paterson, also through an anonymous source, went after Mayor Bloomberg.

“You can’t trust him,” Dicker quoted Paterson as saying then. And, in the unkindest cut, Paterson reportedly said Bloomberg “has the same kind of anger that reminds you of Spitzer.”

Months later, Caroline Kennedy got smeared in an effort by Paterson to justify not picking her for a US Senate seat. An anonymous source, later identified as a consultant to the accidental governor, told reporters Kennedy had a “tax problem” and a “potential nanny issue.” So Ravitch is traveling in good company. As for Paterson, he doesn’t even have the decency to do his own dirty work.

Andy’s no ‘vocal’ hero

Andrew Cuomo had a shock-and-awe rollout of his gubernatorial campaign, but since then, not much noise or action. Voters are start ing to grumble. A new Quinnipiac poll finds that 64 percent want him to speak up more about the budget mess, including 58 percent of Democrats. Sur prisingly, 41 percent of all those surveyed say he is “ducking his responsibility.” Overall, the attorney general enjoys a 72-percent favorable rating and a 32-point lead over Republican Rick Lazio. Still, the public is eager to hear his solutions to the state’s trou bles, and Cuomo would be wise to strike while voters are ready to listen. In politics, as in life, tomorrow isn’t guaranteed.

Ummm . . . how’s that again?

HEAD-SCRATCHING headline of the day, in the Financial Times: “Shouting set to be muted at G20 talks.”